MỘT SỐ ĐẶC ĐIỂM HÌNH THÁI KHỚP CẮN HỞ NGƯỜI VIỆT NAM TRÊN PHIM SỌ NGHIÊNG TELE TỪ XA (CEPHALOMETRICS)

Abstract

Anterior open bite (AOB) is a malocclusion that greatly affects function and aesthetics. Besides, long-term stability of AOB malocclusion is considered challenge for orthodontists. This study aims to describe some morphological characteristics of 36 Vietnamese subjects with anterior open bite between the ages of 10 and 18 years old who had presented the Hanoi Central Odonto-Stomatology Hospital and School of Odonto - Stomatology, Hanoi Medical University. The results of research showed that anterior open bite in Vietnamese people is a rare type of malocclusion. It is more common in women, but no statistically significant difference was found between the genders. Most of the subjects had moderate anterior open bite (-1.39±0.499 mm). The largest proportion is class III skeletal (n=15; 41.7%), the lower anterior facial height (LAFH) is 63.41±6.185mm (female) and 68.29±5,341mm (male). The posterior/anterior facial height ratio (PFH/AFH) = 0.651±0.057. The overbite depth indicator (ODI) is 61.25±9,241, the antero-posterior dysplasia indicator (APDI) is 86.97±11,597, the combined factor (CF) is 148.22±8.642. The height of the maxillary and mandibular first molars relative to the palatal plane and mandibular plane, respectively, is d(U6,PP) = 21.83±2.22 and d(L6,MP) 29.33 ±3,341. Conclusion: Anterior open bite in subjects with permanent teeth (10-18 years old) occurs more frequently in skeletal class III pattern. The majority of subjects had moderate degree of open bite. They showed the characteristics of increasing the anterior facial height and has a hyperdivergent skeletal pattern.